Cannes Rocked by Another High-Profile Jewelry Heist

UPDATED: A diamond necklace worth $2.6 million disappeared from a party attended by Paris Hilton and Sharon Stone at the exclusive Hotel Du Cap-Eden-Roc.

The Cannes Film Festival has been hit by yet another suspected high-profile theft, after a diamond necklace worth $2.6 million (2 million euros) vanished from a star-studded party, according to Swiss luxury jeweler De Grisogono.

PHOTOS: 'The Bling Ring' Steals the Spotlight at Cannes Premiere

De Grisogono founder and creative director Fawaz Gruosi said in a statement released to The Hollywood Reporter: “These incidents are rare; it is actually the first time it happened in our 20-year history. However when they occur one must be proactive," he said, adding that the company is cooperating with authorities. A police report has been filed and an investigation is underway by local law enforcement.

Tuesday night's party at the famed Hotel du Cap-Eden-Roc was to celebrate the brand's 20th anniversary and showcased their High Jewelry Collection, with Sharon Stone, Paris Hilton, Alessandra Ambrosio, and Chris Tucker among the 700 guests. The necklace was discovered as missing after the party was over -- despite the presence of over 80 security guards at the event.

If indeed a burglary, the heist would mark the third high-profile theft to rock the festival.

Swiss jeweler, Chopard, lost jewelry pieces worth $1.4 million the first week of the festival, when a company employee's room at the Suite Novotel Cannes Centre was broken into and an entire safe was removed from the wall.

And just days later, China Film Group vice president Zhang Qiang, one of the most powerful representatives from the Chinese film industry to attend the festival, had all of his belongings stolen from his hotel room, leading him to skip an exclusive press conference he was set to attend with Keanu Reeves to promote the actor’s directorial debut, Man of Tai Chi, which China Film Group is co-producing. The studio boss later wrote on Weibo (China’s version of Twitter), “Security in France is so bad, and the [people] are so arrogant …This film festival is not worth mentioning!”